Placebo response in pharmacological trials in patients with functional dyspepsia-A systematic review and meta-analysis

BACKGROUND

Pharmacological trials in functional dyspepsia (FD) are associated with high placebo response rates. We aimed to identify the magnitude and contributing factors to the placebo response.

METHODS

We conducted a systematic review and meta-analysis including randomized controlled trials (RCTs) with a dichotomous outcome in adult patients with FD that compared an active pharmacotherapeutic treatment with placebo. Our main outcome was identification of the magnitude of the pooled placebo response rate for the following endpoints: symptom responder, symptom-free responder, adequate relief responder, and combined endpoint responder (i.e., the primary endpoint of each specific trial regarding treatment response). Several putative moderators (i.e., patient, disease, and trial characteristics) were examined.

KEY RESULTS

We included 26 RCTs in our analysis. The pooled placebo response rate was 39.6% (95% CI 30.1-50.0) using the symptom responder definition, 20.5% (12.8-31.0) using the symptom-free responder definition, 38.5% (33.8-43.6) using the adequate relief responder definition, and 35.5% (31.6-39.7) using the combined endpoint responder definition. A lower overall baseline symptom score was significantly associated with a higher placebo response rate. No other moderators were found to significantly impact the placebo response rate. Due to the lack of data, no analyses could be performed according to individual FD subtypes or symptoms.

CONCLUSIONS AND INFERENCES

The pooled placebo response rate in pharmacological trials in FD is about 39%, depending on which responder definitions is used. Future trials should consider applying an entry criterion based on minimal level of symptom severity to decrease the placebo response. We also suggest separate reporting of core FD symptoms pending more concrete harmonization efforts in FD trials.

1254Comorbidity of atopic diseases and gastroesophageal reflux in adults: a co-twin control study

Background

Gastroesophageal reflux disease (GERD) is the most common non-allergic comorbidity in adults with asthma, however comorbidity with other atopic diseases such as eczema and hayfever is unclear. The objective was to assess the comorbidity of GERD with atopic diseases in adults, and to investigate possible mechanisms including genetic and affective factors.

Methods

A co-twin control study harnessing 46 583 adult Swedish twins. Questionnaires on health status were linked to national patient and prescribed drug register data. Within twin-pair comparisons were made between unpaired, monozygotic (MZ) and dizygotic (DZ) twins to assess common genetic liability. Affective traits (depression, anxiety and neuroticism) were added to models to assess their role in comorbidity.

Results

The risk of GERD in those with asthma was OR1.52 (95% CI 1.38, 1.68); hayfever OR1.22 (95%CI 1.12, 1.34); and eczema OR1.23 (95%CI 1.10, 1.38). Within twin-pair associations attenuated in decreasing order of shared genetics for all atopic diseases e.g. self-report asthma with GERD: DZ twins adjOR1.41 (95%CI 0.96, 2.08), MZ twins adjOR1.24 (95%CI 0.82, 1.87). Adjusting for affective traits only slightly attenuated the comorbidity associations.

Conclusions

GERD is a common comorbidity in adults with asthma, hayfever and/or eczema. We found evidence for shared genetic factors but not for affective traits.

Key messages

GERD is a common comorbidity not only in adults with asthma, but also in adults with eczema or hayfever. Twin research has revealed evidence for a common genetic liability to explain comorbidity.

Transdiagnostic internet-delivered cognitive-behaviour therapy (CBT) for adults with functional gastrointestinal disorders (FGID): A feasibility open trial

Many people with functional gastrointestinal disorders (FGIDs) face significant barriers in accessing psychological treatments that are known to reduce symptoms and their psychological sequelae. This study examined the feasibility and initial outcomes of a transdiagnostic and internet-delivered cognitive behaviour therapy (iCBT) intervention, the Chronic Conditions Course, for adults with functional gastrointestinal disorders (FGIDs). A single-group feasibility open trial design was employed and administered to twenty seven participants. The course ran for 8 weeks and was provided with weekly contact from a Clinical Psychologist. Seventy percent of participants completed the course within the 8 weeks and 81.5% provided data at post-treatment. High levels of satisfaction were observed and relatively little clinician time (M = 42.70 min per participant; SD = 46.25 min) was required. Evidence of clinical improvements in FGID symptoms (ds ≥ 0.46; avg. improvement ≥21%), anxiety symptoms (ds ≥ 0.99; avg. improvement ≥42%), and depression symptoms (ds ≥ 0.75; avg. improvement ≥35%) were observed, which either maintained or continued to improve to 3-month follow-up. Evidence of improvement was also observed in pain catastrophising and mental-health related quality of life, but not physical-health related quality of life. These findings highlight the potential value of transdiagnostic internet-delivered programs for adults with FGIDs and support for the conduct of larger-scale controlled studies.

Asia-Pacific consensus on the management of gastro-oesophageal reflux disease: an update focusing on refractory reflux disease and Barrett's oesophagus

OBJECTIVE

Since the publication of the Asia-Pacific consensus on gastro-oesophageal reflux disease in 2008, there has been further scientific advancement in this field. This updated consensus focuses on proton pump inhibitor-refractory reflux disease and Barrett's oesophagus.

METHODS

A steering committee identified three areas to address: (1) burden of disease and diagnosis of reflux disease; (2) proton pump inhibitor-refractory reflux disease; (3) Barrett's oesophagus. Three working groups formulated draft statements with supporting evidence. Discussions were done via email before a final face-to-face discussion. We used a Delphi consensus process, with a 70% agreement threshold, using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria to categorise the quality of evidence and strength of recommendations.

RESULTS

A total of 32 statements were proposed and 31 were accepted by consensus. A rise in the prevalence rates of gastro-oesophageal reflux disease in Asia was noted, with the majority being non-erosive reflux disease. Overweight and obesity contributed to the rise. Proton pump inhibitor-refractory reflux disease was recognised to be common. A distinction was made between refractory symptoms and refractory reflux disease, with clarification of the roles of endoscopy and functional testing summarised in two algorithms. The definition of Barrett's oesophagus was revised such that a minimum length of 1 cm was required and the presence of intestinal metaplasia no longer necessary. We recommended the use of standardised endoscopic reporting and advocated endoscopic therapy for confirmed dysplasia and early cancer.

CONCLUSIONS

These guidelines standardise the management of patients with refractory gastro-oesophageal reflux disease and Barrett's oesophagus in the Asia-Pacific region.

Reviewing the evidence base for the peripheral sensory examination

BACKGROUND

Many students find the peripheral sensory examination confusing. We set out to summarise the evidence base in order to provide guidance on the most useful manoeuvres.

METHODS

We performed a literature review starting with 5 secondary sources, supplemented by a literature search on MEDLINE.

RESULTS

A useful approach to neuropathy is to divide these into large fibre sensory neuropathy (LFSN) in which vibration and proprioception are affected, and small fibre sensory neuropathy (SFSN) in which pain and temperature are affected. Positive sensory symptoms such as burning, electric or sunburn pain point to a SFSN; negative symptoms such as loss of sensation, numbness or deep pain point to a LFSN. If LFSN is suspected, the most reproducible and best studied physical examination is a 10 g monofilament, but vibration sense is also useful. There is much less data on the best physical examination for a SFSN. The most appropriate diagnostic test for SFSN is quantitative sensory testing, whereas for LFSN a nerve conduction study is indicated.

CONCLUSIONS

A modest amount of evidence is available to guide peripheral sensory examination but more research is needed.

A re-evaluation of the scratch test for locating the liver edge

BACKGROUND

A reliable and accurate estimation of liver size by physical examination is an important aspect of the clinical assessment of a patient. The scratch test uses auscultation to detect the lower liver edge by using the difference in sound transmission through the abdominal cavity over solid and hollow organs. The test is thought to be particularly useful if the abdomen is tense, distended, obese, or very tender. Although the sign is often taught to medical students and residents, the value of the technique for detecting the liver edge has become controversial.

METHODS

The study was performed in two parts. In the first part, 18 patients undergoing upper abdominal ultrasound as outpatients were randomly selected and the scratch test was performed by two raters independently, followed by ultrasound (USG) as the reference standard. In the second part of the study, the two raters independently performed the scratch test on separate randomly selected patients (15 patients by rater 1, and 16 patients by rater 2), followed by USG.

RESULTS

Agreement between raters on the scratch test was very high, with an intra-class correlation coefficient of 0.97. The agreement between the raters and the USG was 0.37 using Spearman's rho. A Bland -Altman plot indicated that, on average, raters underestimated the distance from the right costal margin to the liver edge by only about 2.4 centimeters compared to USG. This translates into 37% and 54% of raters' estimates falling within 2 and 3 cm of USG estimates. Each unit increase in BMI increased the discrepancy between raters and USG by 0.26 cm (p = 0.012).

CONCLUSION

The scratch test has very high reproducibility and overall agreement between the scratch test and USG was moderate, with a spearman's rho of 0.37. The accuracy may potentially be improved by using the point of initial sound transmission rather than the point of maximal transmission. We conclude that the scratch test deserves further investigation.

Cost of detecting malignant lesions by endoscopy in 2741 primary care dyspeptic patients without alarm symptoms

BACKGROUND & AIMS

Current guidelines recommend empirical, noninvasive approaches to manage dyspeptic patients without alarm symptoms, but concerns about missed lesions persist; the cost savings afforded by noninvasive approaches must be weighed against treatment delays. We investigated the prevalence of malignancies and other serious abnormalities in patients with dyspepsia and the cost of detecting these by endoscopy.

METHODS

We studied 2741 primary-care outpatients, 18-70 years in age, who met Rome II criteria for dyspepsia. Patients with alarm features (dysphagia, bleeding, weight loss, etc) were excluded. All patients underwent endoscopy. The cost and diagnostic yield of an early endoscopy strategy in all patients were compared with those of endoscopy limited to age-defined cohorts. Costs were calculated for a low, intermediate, and high cost environment.

RESULTS

Endoscopies detected abnormalities in 635 patients (23%). The most common findings were reflux esophagitis with erosions (15%), gastric ulcers (2.7%), and duodenal ulcers (2.3%). The prevalence of upper gastrointestinal malignancy was 0.22%. If all dyspeptic patients 50 years or older underwent endoscopy, 1 esophageal cancer and no gastric cancers would have been missed. If the age threshold for endoscopy were set at 50 years, at a cost of $500/endoscopy, it would cost $82,900 (95% CI, $35,714-$250,000) to detect each case of cancer.

CONCLUSIONS

Primary care dyspeptic patients without alarm symptoms rarely have serious underlying conditions at endoscopy. The costs associated with diagnosing an occult malignancy are large, but an age cut-off of 50 years for early endoscopy provides the best assurance that an occult malignancy will not be missed.

Prevalence and correlates of irritable bowel symptoms in a New Zealand birth cohort

AIM

To determine the prevalence and correlates of bowel symptoms and the irritable bowel syndrome (IBS) in a birth cohort of young New Zealanders.

METHODS

Participants in the Dunedin Multidisciplinary Health and Development Study at age 26 completed a validated Bowel Disease Questionnaire expressing their experience of clearly defined symptoms over the previous 12 months.

RESULTS

980 participants (499 male, 481 female, comprising 96% of the birth cohort) completed the questionnaire. Sixty four per cent had at least one of the measured symptoms; abdominal pain was reported in 46.5%, chronic constipation in 9.1%, and chronic diarrhoea in 17.1%. A diagnosis of IBS could be made by using two or more of Manning's diagnostic criteria in 18.8%, three or more criteria in 10.3%, and more than three in 3.3%. Symptoms were more than twice as frequent and severe in females than males.

CONCLUSIONS

Bowel-related abdominal symptoms, including those required for a diagnosis of IBS, are very common in 26-year-old New Zealanders; the prevalence of these symptoms is very similar to that recorded previously in Europe and the USA.

Colon transit scintigraphy using oral indium-111-labeled DTPA. Can scan pattern predict final diagnosis?

Colon transit scintigraphy (CTS) was performed in 100 consecutive patients with idiopathic constipation using oral indium-111-labeled DTPA. Criteria were defined to allow classification of studies as normal, slow transit constipation (STC), or obstructed defecation (OD). Results were compared with final clinical diagnosis in 100 and findings of defecating proctography in 70. Of those with a scintigraphic diagnosis of STC, this was also the final diagnosis in 75% (33 of 44), and the scintigraphic diagnosis of OD was confirmed in 61% (17 of 28). Of 28 normal or equivocal scans, the final diagnosis was STC in only two (4%) but OD in 10 (21%). Fifty-four percent of patients with STC and 71% with OD had abnormal proctograms. The correlation between CTS and proctography was mediocre, occurring in 54% of patients. CTS has a valuable role in the diagnostic work-up of patients with idiopathic constipation.